\section{Hypotheses}
Now that we've looked into the target group and analyzed what the requirements should be for the program, one important element missing is the hypothesis to build the project upon, or, as in this case, a set of hypotheses. It is important that they are both testable and falsifiable. Also, it was chosen to use null hypotheses. A null hypothesis is the opposite of what is wanted. Put another way, we want to reject the null hypothesis, so we can (for now) believe in the alternative hypothesis.

The hypotheses are built on three aspects:
\begin{itemize}
\item Audio alone
\item Visual alone
\item Audio plus Visual
\end{itemize}

It was chosen to have two sets of null hypotheses. Since the goal is to examine whether or not the program has any effect, it is important to measure the target group's skill level both before and after they try it.

This data can be looked at in two different ways. One way is to only look at the measurement after the person has tried the application. Here, only the final score is of interest. It does not matter where the person was before he tried the program, only where he ended up being afterwards.

However, another way to look at the data is to compare the before score with the after score and see how much the person has progressed. This is the difference and can show development of a person's skill level. Maybe one person had zero experience before trying the program, but in the process of playing around with it, he would have increases his skill level. He might not have a big final score, but still have moved his skills a lot.

It was chosen to use both of these perspectives: final score and difference in score. Since the data will be available anyway, it is just a question of how it is analyzed.

Figure \ref{fig:hypothesis} illustrates this the two perspectives. The red dots represent people's scores before trying the application, the green dots after.

\begin{figure}[htbp]
\centering
\includegraphics[width=0.70\textwidth]{images/TheoryDesign/hypothesis_graph}
\caption{There are two ways to look at the data: progress and final score.}
\label{fig:hypothesis}
\end{figure}

\textbf{A: Only audio}

\textbf{V: Only visual (both time domain and frequency domain)}

\textbf{A+V: Audio and Visual together}

\subsection{Null hypothesis 1a (final score)}
For the target group: the average final score of A is equal to or greater than the average final score of A+V. \textit{ScoreFinal(A) $>=$ ScoreFinal(A+V)}.

\subsection{Null hypothesis 1b (difference in score)}
For the target group: the average difference in score of A is equal to or greater than the average difference in score of A+V. \textit{ScoreDifference(A) $>=$ ScoreDifference(A+V)}.

\subsection{Null hypothesis 2a (final score)}
For the target group: the average final score of V is equal to or greater than the average final score of A+V. \textit{ScoreFinal(V) $>=$ ScoreFinal(A+V)}.

\subsection{Null hypothesis 2b (difference in score)}
For the target group: the average difference in score of V is equal to or greater than the average difference in score of A+V. \textit{ScoreDifference(V) $>=$ ScoreDifference(A+V)}.

\subsection{Null hypothesis 3a (final score)}
For the target group: the average final score of A is equal to the average final score of V. \textit{ScoreFinal(A) == ScoreFinal(V)}.

\subsection{Null hypothesis 3b (difference in score)}
For the target group: the average difference score of A is equal to the average difference in score of V. \textit{ScoreDifference(A) == ScoreDifference(V)}.

\subsection{Alternative hypothesis 1a (final score)}
For the target group: the average final score of A is smaller than the average final score of A+V. \textit{ScoreFinal(A) $<$ ScoreFinal(A+V)}.

\subsection{Alternative hypothesis 1b (difference in score)}
For the target group: the average difference in score of A is smaller than the average difference in score of A+V. \textit{ScoreDifference(A) $<$ ScoreDifference(A+V)}.

\subsection{Alternative hypothesis 2a (final score)}
For the target group: the average final score of V is smaller than the average final score of A+V. \textit{ScoreFinal(V) $<$ ScoreFinal(A+V)}.

\subsection{Alternative hypothesis 2b (difference in score)}
For the target group: the average difference in score of V is smaller than the average difference in score of A+V. \textit{ScoreDifference(V) $<$ ScoreDifference(A+V)}.

\subsection{Alternative hypothesis 3a (final score)}
For the target group: the average final score of A is not equal to the average final score of V. \textit{ScoreFinal(A) $!=$ ScoreFinal(V)}.

\subsection{Alternative hypothesis 3b (difference score)}
For the target group: the average difference in score of A is not equal to the average difference in score of V. \textit{ScoreDifference(A) $!=$ ScoreDifference(V)}.